Functional testing in Swift. Simulate the Application flow

Question

I'm trying to perform some really simple feature/functional testing in Swift but I have some doubts that I need to resolve to be able to create useful tests.

I want to verify that a Controller presented by another Controller exists into the Application Navigation Hierarchy (it doesn't matter if the Controller has been presented into a NavigationController, as Modal or whatever).

If I instantiate and show controllers programmatically, directly into the test functions, when I check the On Top controller I always get the Storyboard root controller instead of the controller that I have just instantiated, as if the controllers that I've manually created are never added into the Application Hierarchy.

Here an example of pseudo-code:

func testController(){ 

    // Instantiate a controller 
    let storyBoard:UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle(forClass: self.dynamicType))
    let controller1 = storyBoard.instantiateViewControllerWithIdentifier("Controller1") as? ControllerOneViewController
    controller1.loadView()

    // Call a function that instantiates another controller 
    controller1.pushAnotherController()

    // Test that the current shown controller is what we expect... 
    let rootController = UIApplication.sharedApplication().keyWindow?.rootViewController
    XCTAssert(rootController.self == TheExpectedClass, "Controller is not what we expect")
}

Answer 1

If I instantiate and show controllers programmatically, directly into the test functions, when I check the On Top controller I always get the Storyboard root controller instead of the controller that I have just instantiated, as if the controllers that I've manually created are never added into the Application Hierarchy.

From the code you wrote you are not checking the On Top controller but you are checking root view controller itself (which holds all view controllers in hierarchy including navigation controllers) so thats why you get always storyboard root view controller back. To get top most controller from view controller you can use the following recursive function which takes root view controller and return its top most controller

func topMostController(rootViewController:UIViewController)->UIViewController{

    if let viewController = rootViewController as? UINavigationController{

        return topMostController(viewController.visibleViewController)
    }

    if let viewController = rootViewController.presentedViewController{

        return topMostController(viewController)
    }

    return rootViewController
}

and then in your testing function check the controller that this function returns

func testController(){ 

// Instantiate a controller 
let storyBoard:UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle(forClass: self.dynamicType))
let controller1 = storyBoard.instantiateViewControllerWithIdentifier("Controller1") as? ControllerOneViewController
controller1.loadView()

// Call a function that instantiates another controller 
controller1.pushAnotherController()

// Test that the current shown controller is what we expect... 
let rootController = UIApplication.sharedApplication().keyWindow?.rootViewController
XCTAssert(topMostController(rootController) == TheExpectedClass, "Controller is not what we expect")
}